Knee - That part of a column of a knee-type milling machine which carries the saddle and the table and provides the machine with vertical feed adjustments. Also, the name of a precision angle called a Toolmakers Knee.

K - Symbol used in linear elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation, the factor is call the critical stress-intensity factor (KIc) or fracture toughness. Various subscripts denote loading conditions or fracture toughness. Units are Mpa/mm or ksi/in

Kahlbaum Iron - An iron of more than 99.975% purity, produced in Germany.

Kaldo Process - A method of producing steel from molten iron, using an inclined rotating converter and a water cooled oxygen lance inserted through the converter mouth. Originating in Sweden, this process is no longeer in use in the UK

Kaolin - The purest form of China clay consisting of silicate of aluminum.

Kappa Carbide - A carbide of iron (Fe23, C6) in which all or part of the iron may be replaced by chromium, molybdenum, and/or tungsten.

Kayser Hardness Test - A method for determining the true hardness of metals at high temperatures.

KC (Plane-stress fracture toughness) - The value of stress intensity at which crack propagation becomes rapid in sections thinner than those in which plane-strain conditions prevail. Units are MPa/m or ksi/in.

Kelvin Temperature Scale - One in which the unit of measurement equals that of the centigrade degree and according to which absolute zero is 0 degrees, equivalent to -273.16 C.

Kerf - The width of a cut.

Key - One of several types of small metal objects designed to fit mating slots in a shaft and the hub of a gear or pulley to provide a positive drive between them. Alos, the name of the T-handle wrench used on chucks.

Killed Steel - The term killed indicates that the steel has been sufficiently deoxidized to quiet the molten metal when poured into the ingot mold. The general practice is to use aluminum ferrosilicon or manganese as deoxidizing agents. A properly killed steel is more uniform as to analysis and is comparatively free from aging. However, for the same carbon and manganese content Killed Steel is harder than Rimmed Steel. In general all steels above 0.25% carbon are killed, also all forging grades, structural steels from 0.15% to 0.25% carbon and some special steels in the low carbon range. Most steels below 0.15% carbon are rimmed steel.

Kiln - An oven or furnace for burning, calcimining or drying a substance.

Kiln Marks - Irregularities on the surface of refractors caused by deformation under load during burning.

Kiln-Dried - Lumber artificially dried in a specially designed enclosure or lumber kiln.

Kilovolt (kV) - Unit of electrical potential equal to 1,000 volts.

Kilovolts Constant Potential - The potential in kilovolts of a constant voltage generator.

Kilovolts Peak - The crest value of the potential wave in kilovolts. When only one half of the wave is used, the crest value is to be measured on this half of the wave.

Kind Band (deformation) - In polycrystalline materials, a volume of crystal that has rotated physically to accommodate differential deformation between adjoining parts of a grain while the band itself has deformed homogeneously. This occurs by regular bending of the slip lamellae along the boundaries of the band.

Kink - (1) for rolled products, an abrupt bend or deviation from flat which is caused by localized bending during handling. (2) for extrusions, an abrupt deviation from straightness. A kink can be caused by handling.

Knoop Hardness Number (HK) - A number related to the applied load and to the projected area of a rhombic-based diamond indentor, with edge angles of 172 1/2 30' and 130 1/2.

Knoop Hardness Test - A micro hardness test in which an elongated pyramidical diamond is pressed into the surface.

Knurl - A decorative gripping surface of straight-line or diagonal design made by uniformly serrated rolls called knurls.

Knurling - The process of finishing a part by scoring (pressing) patterns on the surface of the work.

KOP Pusher - A machine that pushes the KOP on the ground, off the table after processing.

KOP Recirculating Filter - A filter that cleans the KOP pusher tank hydraulic oil by constantly recirculating the oil from the tank through the filter and then back to the tank.

KVA - Stands for kilo-volt-amperes. It is a measurement of electrical power. It is made up of reactive power (KVAR) and real power (KW). It can be derived by multiplying the voltage by the current.

Killed Steel - Steel deoxidized with a strong deoxidizing agent, such as silicon or aluminum, to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.

Killed Steel - Steel deoxidized with a strong deoxidizing agent such as silicon or aluminum in order to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.